title: Expression of Pseudomonas fluorescens D-galactose dehydrogenase in E. coli.
abstract: To investigate the heterologous expression of Pseudomonas genes in Escherichia coli we have cloned P. fluorescens DNA in an E. coli [cosmid] system. A colony bank representing the whole P. fluorescens chromosome was screened immunologically using a modification of the method described by Broome and Gilbert (1978). Radioactive labelling of the antibodies was replaced by conjugation with horseradish peroxidase. Among 523 E. coli colonies one was D-galactose dehydrogenase-positive. The expression of this enzyme in primary clones was lower than in the uninduced Pseudomonas. Subcloning of the D-galactose dehydrogenase gene, in vitro mutagenesis of the DNA, and coupling to a strong E. coli promoter yielded an E. coli strain that produces 90 times more of the enzyme than the induced P. fluorescens.
mesh_terms: D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics*; D002237:Carbohydrate Dehydrogenases / Q000235:genetics*; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics; D005691:Galactose Dehydrogenases / Q000096:biosynthesis / Q000235:genetics*; D005786:Gene Expression Regulation; D010957:Plasmids; D011551:Pseudomonas fluorescens / Q000201:enzymology / Q000235:genetics*; D013045:Species Specificity
chemical_list: D001426:Bacterial Proteins; D002237:Carbohydrate Dehydrogenases; D005691:Galactose Dehydrogenases